A stretch of N Street between 16th and 17th streets in Sacramento was closed temporarily to traffic following a report of an explosion and smoke coming from a manhole.

Sacramento firefighters responded about 6:30 p.m. Wednesday to what they initially believed was a hazardous materials threat after the event, which left green and brown smoke rising from the manhole. A two-square-block area was closed and residents were directed to shelter in place.

Fire officials said they subsequently determined that the explosion occurred in an electrical vault and was not tied to hazardous materials. No injuries were reported.

Sacramento Municipal Utility District crews were called in to resolve the problem.

Cara Chatfield, a spokeswoman for SMUD, said a joint in a cable failed, releasing energy that lifted the manhole cover. She said moisture collects at the bottom of the deep vaults and what appeared to be smoke likely was steam. Power service in the area was not affected.

Shortly before 7:30 p.m., the area was reopened to pedestrian and auto traffic.

Residents in the immediate area had been advised to stay indoors as a precaution.